turning down the Argon for TIGging

I'm trying to conserve argon. It's $42 including tax per 150 cf bottle here in NC and I'm running thru it too fast. I've always had my flow rate at 15 cfm like mom taught me but I'm experimenting dialing it down. I've got it down to 13 cfm now with no apparent problems. I have the cheap dial type flow gauge that came with the machine.

I should also describe my setup and welds. Dynasty 200 at 200A, 3/32 lanthanated electrode, gas lenses with #7 cup. I'm doing fillets at various angles with 3/16 throats in A500 structural steel. Using E70S-6 filler and 2 second post flow. I weld for 1.5 minutes and wait 6 minutes. I would estimate my travel speed at 1.5" per minute. (I realize a pro would probably use a bigger machine for this. I'm and owner/builder and this equipment will have to do.)

My main question is: Is it always obvious to the eye when welding if you are not using enough argon on low carbon steel?

--zeb

Reply to
zeb
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Can't comment on your question, but I strongly suggest you pick up a used

251 cf oxygen owner cylinder and take it in and swap it for a 251 of argon. You may be startled to find that the filling cost is nearly the same for a 251 as it is for a 150. At least it is around here. (Seattle)

GWE

zeb wrote:

Reply to
Grant Erwin

Given that you could weld "low carbon steel" using oxy/acetylene I suspect that the shielding gas is doing little to protect the parent metal other then to reduce or eliminate the surface discoloration.

But to answer your question, if the shielding gas is 100% effective you would have no coloration of the welded area.

Cheers,

Bruce (bruceinbangkokatgmaildotcom)

Reply to
Bruce In Bangkok

Reply to
RoyJ

I am not exactly sure what sort of equipment you have as far as solenoids and flow meter regulator. Using a short non expandable hose from the regulator to the machine could help. My regulator makes 50 pounds when there is no flow and I suppose 50 pounds just before the adjustment knob all the time. What happens is the hose from the regulator blows up like a balloon and makes a great big puff when the solenoid kicks in. I used to have a short hose more like an oxy acetylene type hose but for whatever reason I got a new black balloon like one from the welding shop.

The inert gas shields but also is the medium which the arc works in. If air gets in you get bubbling and pores which are about impossible to weld over and have to be ground out or removed some other way unless you don't care.

Reply to
fran...123

RoyJ wrote in news:geidnQ1XI8VblUHUnZ2dnUVZ snipped-for-privacy@earthlink.com:

I don't trust my stick skills enough. One of the nice things for me about TIG are the easy restarts and the complete control. The slow pace allows me time to think and assess how the weld is going. The joint also turns corners and extra care is needed there. The stops and restarts of TIG for me are easier to do. Thanks for the advice though, I have none doubt someone could do it as you are describing.

Reply to
zeb

Grant Erwin wrote in news:1BPCl.4290$ snipped-for-privacy@newsfe04.iad:

I'm in NC. I've inquired 3 or 4 times about getting a larger cylinder and they all say the 150 is my only option. 150cf = customer owned, all the other sizes are for outfits with contracts. You make me want to ask again though.

Reply to
zeb

A little off topic but I would like to comment how nice it is to post and read with a real Usenet news reader and a real news server (other than Google). I'm using the free text-only news server news.motzarella.net, and either the XNews or Gravity news readers (still deciding). Highly recommended.

Reply to
zeb

Sigh. 1.5 inches every 7-1/2 minutes on A500. Sigh.

Could I coax you > RoyJ wrote in

Reply to
RoyJ

zeb wrote in news:gri8co$f5o$ snipped-for-privacy@news.motzarella.org:

I just called. It's actually NC state law that customer-owned bottles not exceed 150cf.

Reply to
zeb

And they won't lease the larger bottles to you?

If they will, look at how much the cost per lease is over how much you will save in fewer refills (taking into account the different price per refill). That will let you know if it is worth it to you.

Reply to
Todd Rich

If they didn't cite a specific stature that you can validate, it is almost certainly BS. Much like hydrotesting which is not a legal requirement for privately owned cylinders, only for those that fall under interstate commerce regs, not that it matters with the usual cylinder swaps.

Reply to
Pete C.

If I infer when you say "owner/builder" that you are working on an aircraft, this probably does not apply, but one way to cut gas use is to work in a glovebox, for parts that fit.

Reply to
Ecnerwal

Thread drift snipped:

Get to the quietest place you can get to TIG. Wind or even air flow from a fan will mess it up. Build a small walled area, maybe the size of a box if you do small stuff. If you weld in a closed garage, remember to at least use some type of exhaust, or a fresh air supply to your hood.

Get some practice materials, and do repetetive welds, each time turning down the pressure. Pressure is going to vary with cup size and electrode size.

One pressure does not fit all unless you're working at a shop, and they are providing the gas. As one poster said, consider trading up to a larger size tank, as the cost is reduced. After that, make a chart to record results, and that should give you parameters.

But outside, or in the wind, or in drafts, all bets are off.

HTH

Reply to
Pittman Pirate

Check with other suppliers. See if you can find one used. Check first with all suppliers regarding them filling YOUR customer owned tanks. Some of them are really insane with their policies.

Reply to
Pittman Pirate

My situation was exactly that. The lease guys were cheaper for refills, and I mean about 60% of what the owner cylinder filler was. When figured with the cost of refills and the cost of the lease, it was cheaper to lease over a 5 year span.

Reply to
Pittman Pirate

How often are you refilling your 150?

Call all your local gas suppliers, and ask if they will "RENT" you a larger cylinder by the month. Terminology is important, don't confuse things with the words buy or lease. All the gas suppliers around me like to RENT the large cylinders for $5 to $9 a month. Some do RENT by the year, and give you one or two free months for the single payment.

You usually have to fill out a credit app and maintain OPEN account status with them to qualify for cylinder rental programs, but that can be handy as well. But they will often lease or sell certain sized cylinders to even cash customers, but it's not the big cylinders.

Reply to
Tim

Hate to tell you but hydrotesting of privately owned cylinders IS a legal requirement. If a tank is out of hydro it legally cannot be refilled. Doesn't matter who owns it. And if it has reached the end of service life it has to be scrapped. The ONLY part that causes misunderstanding is usually the item that states that IF the cylinder is full and in service at the time the hydro date comes up it does NOT have to be emptied/used and taken for hydro testing, however once it is empty it has to pass hydro before it can legally be refilled. If you know of a place that looks the other way and fills out of date bottles and you can live with the results if a bottle fails then that's your choice.

Reply to
Steve W.

Ecnerwal wrote in news: snipped-for-privacy@feeder.motzarella.org:

Nope, I'm welding 30 ft open-web joists --building a err... house.

Reply to
zeb

Still not going to fit in a glovebox - but somewhat surprising to have those be worth building, rather than buying factory made, given that factory-made is down to a fine science.

Reply to
Ecnerwal

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